UPDATED! Version 2.5.5** 3/21/2017
- Added new method for automatic skin set.
- Removed the old method for skin set (there is no looping though configuration file anymore).
- Fixed some warning on plugin script.
- Version 2.4.8 Bug is now fixed using the new method.

UPDATED! Version 2.6.0**3/22/2017
- Added a new convar called sm_map_mstay (See the original convar list for info)NOTE: use this version only if you have bug with skins after map change otherwise use 2.5.5

UPDATED! Version 2.6.5**3/24/2017
- Added a new convar called sm_pskin_enable.
- Added a new default key called as "def" in admin_skins.ini.
- Fixed some Handles was not closing.
- Fixed some small bugs.

The configuration file looks good and should work .
And about your question , the answer is no , not until you drop your weapons and retake them but your question made me to think about it and will make it possible in a future release.

UPDATED! Version 2.6.7**3/26/2017
- Fixed weapons drop on each spawn.
- Added a new convar called sm_force_arms_change (more info in first post).
- Added immediate arms set on choosing new skin during the round.
- Arms fix improved.